The present invention relates to couplers between transmitters and receivers and in particular to couplers for transmission lines or for coupling peripherals to computers.
In the computer art, it is known to relieve the processing unit, usually termed the CPU, of the task of managing the input/output lines or the peripherals by means of microprocessors which are connected between the processing unit and the various peripheral devices.
The use of microprocessors calls for the employment of a program which is written employing instructions of a kind defined by the operating manual for the microprocessor. Each instruction naturally has corresponding to it a series of microinstructions and the execution of an instruction requires a more or less great number of microprocessor cycles. The execution of one microinstruction generally requires only a single cycle. Consequently, programming a microprocessor to allow it to be used in a coupler restricts the speed of data exchanges along transmission or peripheral lines, particularly if the transmission lines and the operations to be performed on the data are large in number.